1. Field of Invention
The present invention relates to a coil apparatus for medically treating a urinary incontinence patient by generating magnetic flux to thereby induce an eddy current in the body of the patient when a coil apparatus is supplied with a pulse current.
2. Related Art
There is proposed an apparatus for medically treating a urinary incontinence patient by stimulating the pelvic floor muscle group, the purdendal nerve, or the like, of the patient with an eddy current induced by magnetic flux generated from a coil and given to the patient (JP-A-9-276418, JP-A-10-234870), in place of a well-known electric stimulation apparatus for medically treating a urinary incontinence patient by attaching stimulation electrodes and giving an electric pulse to the patient.
The proposed apparatus has made it possible to medically treat a urinary incontinence patient, noninvasively, with his or her clothes on, without pain and shock to the patient. Moreover, the proposed apparatus has made it possible to reduce electric power consumption.
Urinary incontinence is roughly classified into stress incontinence and urge incontinence. For giving medical treatment for stress incontinence, it is necessary to stimulate the pelvic floor muscle group of the patient and reinforce the weakened muscular system, such as the weakened pelvic floor muscle group, the weakened urethral sphincter group, or the like, of the patient to thereby strengthen the urethra-tightening force. On the other hand, for giving medical treatment for urge incontinence, it is necessary to stimulate the purdendal nerve and branches thereof derived from the second, third and fourth sacral nerves to thereby suppress the reflexive involuntary contraction of the bladder.
In order to perform such medical treatment by use of magnetic force, it is therefore important that the magnetic flux can reach the pelvic floor muscle group or the purdendal nerve and branches thereof efficiently.
In the coil apparatus, there are two kinds of coils for generating magnetic flux. One is an air-core coil, and the other is a cored coil. The air-core coil has two features as follows.
(1) It is easy to generate an intensive magnetic field because the magnetic field can be intensified in proportion to the intensity of the current.
(2) Magnetic lines of flux diverge from the center of the coil, so that magnetic flux reaches a wide region.
Accordingly, the air-core coil is advantageous in the case where the region to be stimulated is extended to a wide range. The air-core coil is, however, unsuitable for stimulation of a certain limited region. That is, the air-core coil has a disadvantage in that a wider region than intended is stimulated, and a large amount of electric power is consumed.
On the other hand, the cored coil has a feature that magnetic lines of flux can be concentrated in the core to thereby effectively stimulate a specific region. Hence, the cored coil has an advantage in that electric power consumed by the cored coil is very little in comparison with the air-core coil if the region to be stimulated is limited to a specific region. Therefore, a W-shaped core composed of two U-shaped core elements is heretofore used so that a considerably wide region can be stimulated, though, with the cored coil used. FIG. 12 shows the configuration of the W-shaped core. As shown in FIG. 12, the two U-shaped core elements 20 and 21 have one-side end portions fixed to each other at a fixation portion. The coil 22 is wound on the fixation portion of the core. This coil apparatus is used so that the core elements 20 and 21 are directed in a direction of the front-to-behind of the patient.
In such a coil apparatus, however, magnetic lines of flux are flattened (horizontally) in the direction of the front-to-behind of the patient so as to pass through the region of the patient to be stimulated. Hence, the coil apparatus has a disadvantage in that it does not stimulate all over the pelvic floor muscle group or the purdendal nerve.
Namely, as shown in FIG. 13(a),the pelvic floor muscle group, which is located below a bone marrow, supports a bladder, a vagina, a uterus, a rectum or the like and is defined by levator consisting of a coccygeus muscle, an iliococcygeus muscle, pubococcygeus muscle or the like and a puborectal fillet (sling) surrounding the lower part of the rectum. The pelvic floor muscle group spreads in a horizontal direction. Further, second to fourth sacral nerves 101 are located in vicinity of the bladder as shown in FIGS. 13(a) and (b). That is, the second to fourth sacral nerves serve as a trunk branching to the purdendal nerve controlling an external urethral sphincter 102 contracting the urethra. As viewed from the bottom of a buttocks, the second to fourth sacral nerves are innervated in right and left directions (FIG. 13(b) only shows in right side. Left side thereof is omitted). Further, the pelvic nerve for contracting the sphincter muscle of the urinary bladder during urination is branched from the second to fourth sacral nerves.
Namely, the inventors find that it is necessary to sufficiently apply the magnetic flux to not only front-to-behind direction of the patient but also right-to-left direction thereof in consideration of width of the pelvic floor muscle group and right-to-left direction of the second to fourth sacral nerves and the purdendal nerve branched from the sacral nerves.
The present invention has been achieved in consideration of the disadvantages in the background art, and an object of the present invention is to provide a coil apparatus for urinary incontinence treatment, in which: electric power consumption can be reduced; and the region to be stimulated can be stimulated while the regions not to be stimulated are hardly stimulated.
The coil apparatus for urinary incontinence treatment according to the present invention comprises: a core including at least four U- or J-shaped core elements, the four core elements having one-side end portions and counter-side end portions opposite to the one-side end portions respectively, the one-side end portions being directed substantially in one and the same direction, the one-side end portions being fixed to one another at a portion which is defined as a center portion of the core, the counter-side end portions being extended in each direction respectively from the center portion where the one-side end portions are fixed to one another; a coil wound on the core; and a core support member to which the core is attached, the core support member being able to be disposed close or near to a patient.
In the aforementioned configuration, magnetic flux is generated between the fixation portion at which the core elements are fixed to one another and each of the counter-side end portions of at least the four core elements. The magnetic flux reaches all the specific region in the patient""s body but the magnetic flux hardly reaches the other region. Hence, an eddy current is induced in the specific region so that urinary incontinence treatment is performed.
The core in the aforementioned configuration may be replaced by an integrally molded core having substantially the same whole shape of the first-mentioned core.
According to another aspect of the present invention, there can be provided a coil apparatus comprising a core, a coil and a core support member. The core includes a bowl-shaped or closed-end-tube-shaped base portion and a protrudent portion protruded from an inner center of the base portion. The coil is wound on the protrudent portion of the core. The core support member is attached close or near to a patient in a state in which the core is attached to the core support member.
Thus, magnetic flux is generated between the protrudent portion of the core and the edge portion of the base portion of the core. The magnetic flux reaches all over the specific region of the patient""s body but hardly reaches the other region. An eddy current is induced in the specific region to perform urinary incontinence treatment.
According to the present invention, the magnetic flux generated from the core applied for a patient to at least forward to behind direction of the pelvic floor muscle group and right to left direction where the second to fourth sacral nerves innervated in said right to left direction or the purdendal nerve branched from the second to fourth sacral nerves.